FIG. 1 schematically illustrates a conventional camera module. As shown in FIG. 1, the camera module 10 is assembled by a flip-chip packaging technology. The camera module 10 comprises a substrate 11 and a chip 12. The substrate 11 has a contact pad 111 and an opening 112. The chip 12 has a sensing region 121 and a connection region 122. A conductive bump 13 is disposed on the connection region 122. Through the conductive bump 13, the contact pad 111 and the connection region 122 are electrically connected with each other, and the substrate 11 and the chip 12 are combined together.
Please refer to FIG. 1 again. The contact pad 111 is disposed around the opening 112 and aligned with the connection region 122. The opening 112 is formed by using a hole-breaking component (not shown) to punch the substrate 11. However, after the hole-breaking component is withdrawn from the substrate 11, the edge of the opening 112 is readily subject to deformation in response to the stress. Under this circumstance, an upturned edge 113 is created at an edge of the opening 112.
During the substrate 11 and the chip 12 are laminated together by the flip-chip packaging technology, the upturned edge 113 may result in some drawbacks. For example, since the upturned edge 113 is protruded upwardly, the gap distance between the substrate 11 and the chip 12 is increased. Moreover, since the contacting point between the upturned edge 113 and the chip 12 acts like a fulcrum, a torque is readily generated to cause damage of the conductive bump 13. Under this circumstance, the adhesion instability between the substrate 11 and the chip 12 is largely increased.
FIG. 2 schematically illustrates another conventional camera module. For eliminating the adverse effect of the height of the upturned edge 113, a plurality of conductive bumps 13 are placed on the same connection region 122. In such way, the possibility of allowing the contacting point between the upturned edge 113 and the chip 12 to be formed as a fulcrum will be minimized. However, since the heights of the contact pads 111 corresponding to different connection regions 122 are not always identical, some drawbacks occur. For example, if the same number of conductive bumps 13 are placed on all of the connection regions 122, unnecessary packaging cost is increased. In addition, the uneven heights of the contact pads 111 may result in skew of the chip 12.